HP 54501A - The Command Tree; Command Types

The
Command
Tree
The
command tree
(figure
4-1) shows
all
commands
in
the
HP
54501A
and
the
relationship
of
the
commands
to
each
other.
The IEEE 488.2
common
commands
are
not
listed
as
part
of
the
command
tree
since
they
do
not
affect
the
position
of
the
parser
within the
tree.
After
a
<
NL
>
(linefeed
-
ASCII decimal
10)
has
been sent
to
the
instrument,
the
parser
will
be
set
to
the
"root"
of
the
command
tree.
Command
Types
The
commands
for
this
instrument
can
be
placed
into
three
types.
The
three
types
are:
Common
commands.
Common
commands
are
independent
of
the
tree,
and
do
not
affect
the
position
of
the
parser
within
the
tree.
These
differ
from
root
level
commands
in that
root
level
commands
place
the
parser
back
at the
root.
Example:
»RST.
Root
Level
commands.
The
root
level
commands
reside
at
the
root
of
the
command
tree.
These
commands
are
always parsable
if
they
occur
at
the
beginning
of
a
program
message,
or are
preceded
by
a
colon.
Example:
:AUTOSCALE
Subsystem
commands.
Subsystem
commands
are
grouped
together
under
a
common
node
of
the
tree,
such
as
the
TIMEBASE
commands.
Programming
and Documentation
Conventions
4-4
HP
54501A
Programming